.header {
  width: 100%;
  display: flex;
}
.header .header-logo {
  width: 50%;
  height: 20px;
}
.header .header-menu {
  width: 50%;
  display: flex;
  justify-content: space-between;
  align-items: center;
  background-color: #fff;
  font-size: 18px;
  padding: 5px 20px;
}
.header .header-menu .header-menu-item {
  padding: 5px 10px;
  transition: background-color 0.3s ease-in-out;
  position: relative;
}
.header .header-menu .header-menu-item::after {
  content: "";
  position: absolute;
  width: 100%;
  height: 2px;
  bottom: 0;
  left: 0;
  background-color: #000;
  opacity: 0;
  transition: opacity 0.3s ease-in-out;
}
.header .header-menu .header-menu-item:hover::after {
  opacity: 1;
}
